tasn_dec.c revision 280304
1/* tasn_dec.c */
2/*
3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
4 * 2000.
5 */
6/* ====================================================================
7 * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in
18 *    the documentation and/or other materials provided with the
19 *    distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 *    software must display the following acknowledgment:
23 *    "This product includes software developed by the OpenSSL Project
24 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 *    endorse or promote products derived from this software without
28 *    prior written permission. For written permission, please contact
29 *    licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 *    nor may "OpenSSL" appear in their names without prior written
33 *    permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 *    acknowledgment:
37 *    "This product includes software developed by the OpenSSL Project
38 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com).  This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59
60#include <stddef.h>
61#include <string.h>
62#include <openssl/asn1.h>
63#include <openssl/asn1t.h>
64#include <openssl/objects.h>
65#include <openssl/buffer.h>
66#include <openssl/err.h>
67
68static int asn1_check_eoc(const unsigned char **in, long len);
69static int asn1_find_end(const unsigned char **in, long len, char inf);
70
71static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
72                        char inf, int tag, int aclass, int depth);
73
74static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen);
75
76static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
77                           char *inf, char *cst,
78                           const unsigned char **in, long len,
79                           int exptag, int expclass, char opt, ASN1_TLC *ctx);
80
81static int asn1_template_ex_d2i(ASN1_VALUE **pval,
82                                const unsigned char **in, long len,
83                                const ASN1_TEMPLATE *tt, char opt,
84                                ASN1_TLC *ctx);
85static int asn1_template_noexp_d2i(ASN1_VALUE **val,
86                                   const unsigned char **in, long len,
87                                   const ASN1_TEMPLATE *tt, char opt,
88                                   ASN1_TLC *ctx);
89static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
90                                 const unsigned char **in, long len,
91                                 const ASN1_ITEM *it,
92                                 int tag, int aclass, char opt,
93                                 ASN1_TLC *ctx);
94
95/* Table to convert tags to bit values, used for MSTRING type */
96static const unsigned long tag2bit[32] = {
97    /* tags  0 -  3 */
98    0, 0, 0, B_ASN1_BIT_STRING,
99    /* tags  4- 7 */
100    B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN,
101    /* tags  8-11 */
102    B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
103    /* tags 12-15 */
104    B_ASN1_UTF8STRING, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
105    /* tags 16-19 */
106    B_ASN1_SEQUENCE, 0, B_ASN1_NUMERICSTRING, B_ASN1_PRINTABLESTRING,
107    /* tags 20-22 */
108    B_ASN1_T61STRING, B_ASN1_VIDEOTEXSTRING, B_ASN1_IA5STRING,
109    /* tags 23-24 */
110    B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME,
111    /* tags 25-27 */
112    B_ASN1_GRAPHICSTRING, B_ASN1_ISO64STRING, B_ASN1_GENERALSTRING,
113    /* tags 28-31 */
114    B_ASN1_UNIVERSALSTRING, B_ASN1_UNKNOWN, B_ASN1_BMPSTRING, B_ASN1_UNKNOWN,
115};
116
117unsigned long ASN1_tag2bit(int tag)
118{
119    if ((tag < 0) || (tag > 30))
120        return 0;
121    return tag2bit[tag];
122}
123
124/* Macro to initialize and invalidate the cache */
125
126#define asn1_tlc_clear(c)       if (c) (c)->valid = 0
127/* Version to avoid compiler warning about 'c' always non-NULL */
128#define asn1_tlc_clear_nc(c)    (c)->valid = 0
129
130/*
131 * Decode an ASN1 item, this currently behaves just like a standard 'd2i'
132 * function. 'in' points to a buffer to read the data from, in future we
133 * will have more advanced versions that can input data a piece at a time and
134 * this will simply be a special case.
135 */
136
137ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
138                          const unsigned char **in, long len,
139                          const ASN1_ITEM *it)
140{
141    ASN1_TLC c;
142    ASN1_VALUE *ptmpval = NULL;
143    if (!pval)
144        pval = &ptmpval;
145    asn1_tlc_clear_nc(&c);
146    if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0)
147        return *pval;
148    return NULL;
149}
150
151int ASN1_template_d2i(ASN1_VALUE **pval,
152                      const unsigned char **in, long len,
153                      const ASN1_TEMPLATE *tt)
154{
155    ASN1_TLC c;
156    asn1_tlc_clear_nc(&c);
157    return asn1_template_ex_d2i(pval, in, len, tt, 0, &c);
158}
159
160/*
161 * Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and
162 * tag mismatch return -1 to handle OPTIONAL
163 */
164
165int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
166                     const ASN1_ITEM *it,
167                     int tag, int aclass, char opt, ASN1_TLC *ctx)
168{
169    const ASN1_TEMPLATE *tt, *errtt = NULL;
170    const ASN1_COMPAT_FUNCS *cf;
171    const ASN1_EXTERN_FUNCS *ef;
172    const ASN1_AUX *aux = it->funcs;
173    ASN1_aux_cb *asn1_cb;
174    const unsigned char *p = NULL, *q;
175    unsigned char *wp = NULL;   /* BIG FAT WARNING! BREAKS CONST WHERE USED */
176    unsigned char imphack = 0, oclass;
177    char seq_eoc, seq_nolen, cst, isopt;
178    long tmplen;
179    int i;
180    int otag;
181    int ret = 0;
182    ASN1_VALUE **pchptr, *ptmpval;
183    if (!pval)
184        return 0;
185    if (aux && aux->asn1_cb)
186        asn1_cb = aux->asn1_cb;
187    else
188        asn1_cb = 0;
189
190    switch (it->itype) {
191    case ASN1_ITYPE_PRIMITIVE:
192        if (it->templates) {
193            /*
194             * tagging or OPTIONAL is currently illegal on an item template
195             * because the flags can't get passed down. In practice this
196             * isn't a problem: we include the relevant flags from the item
197             * template in the template itself.
198             */
199            if ((tag != -1) || opt) {
200                ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
201                        ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
202                goto err;
203            }
204            return asn1_template_ex_d2i(pval, in, len,
205                                        it->templates, opt, ctx);
206        }
207        return asn1_d2i_ex_primitive(pval, in, len, it,
208                                     tag, aclass, opt, ctx);
209        break;
210
211    case ASN1_ITYPE_MSTRING:
212        p = *in;
213        /* Just read in tag and class */
214        ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
215                              &p, len, -1, 0, 1, ctx);
216        if (!ret) {
217            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
218            goto err;
219        }
220
221        /* Must be UNIVERSAL class */
222        if (oclass != V_ASN1_UNIVERSAL) {
223            /* If OPTIONAL, assume this is OK */
224            if (opt)
225                return -1;
226            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MSTRING_NOT_UNIVERSAL);
227            goto err;
228        }
229        /* Check tag matches bit map */
230        if (!(ASN1_tag2bit(otag) & it->utype)) {
231            /* If OPTIONAL, assume this is OK */
232            if (opt)
233                return -1;
234            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MSTRING_WRONG_TAG);
235            goto err;
236        }
237        return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0, ctx);
238
239    case ASN1_ITYPE_EXTERN:
240        /* Use new style d2i */
241        ef = it->funcs;
242        return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx);
243
244    case ASN1_ITYPE_COMPAT:
245        /* we must resort to old style evil hackery */
246        cf = it->funcs;
247
248        /* If OPTIONAL see if it is there */
249        if (opt) {
250            int exptag;
251            p = *in;
252            if (tag == -1)
253                exptag = it->utype;
254            else
255                exptag = tag;
256            /*
257             * Don't care about anything other than presence of expected tag
258             */
259
260            ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL,
261                                  &p, len, exptag, aclass, 1, ctx);
262            if (!ret) {
263                ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
264                goto err;
265            }
266            if (ret == -1)
267                return -1;
268        }
269
270        /*
271         * This is the old style evil hack IMPLICIT handling: since the
272         * underlying code is expecting a tag and class other than the one
273         * present we change the buffer temporarily then change it back
274         * afterwards. This doesn't and never did work for tags > 30. Yes
275         * this is *horrible* but it is only needed for old style d2i which
276         * will hopefully not be around for much longer. FIXME: should copy
277         * the buffer then modify it so the input buffer can be const: we
278         * should *always* copy because the old style d2i might modify the
279         * buffer.
280         */
281
282        if (tag != -1) {
283            wp = *(unsigned char **)in;
284            imphack = *wp;
285            if (p == NULL) {
286                ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
287                goto err;
288            }
289            *wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED)
290                                  | it->utype);
291        }
292
293        ptmpval = cf->asn1_d2i(pval, in, len);
294
295        if (tag != -1)
296            *wp = imphack;
297
298        if (ptmpval)
299            return 1;
300
301        ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
302        goto err;
303
304    case ASN1_ITYPE_CHOICE:
305        if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
306            goto auxerr;
307        if (*pval) {
308            /* Free up and zero CHOICE value if initialised */
309            i = asn1_get_choice_selector(pval, it);
310            if ((i >= 0) && (i < it->tcount)) {
311                tt = it->templates + i;
312                pchptr = asn1_get_field_ptr(pval, tt);
313                ASN1_template_free(pchptr, tt);
314                asn1_set_choice_selector(pval, -1, it);
315            }
316        } else if (!ASN1_item_ex_new(pval, it)) {
317            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
318            goto err;
319        }
320        /* CHOICE type, try each possibility in turn */
321        p = *in;
322        for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
323            pchptr = asn1_get_field_ptr(pval, tt);
324            /*
325             * We mark field as OPTIONAL so its absence can be recognised.
326             */
327            ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
328            /* If field not present, try the next one */
329            if (ret == -1)
330                continue;
331            /* If positive return, read OK, break loop */
332            if (ret > 0)
333                break;
334            /* Otherwise must be an ASN1 parsing error */
335            errtt = tt;
336            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
337            goto err;
338        }
339
340        /* Did we fall off the end without reading anything? */
341        if (i == it->tcount) {
342            /* If OPTIONAL, this is OK */
343            if (opt) {
344                /* Free and zero it */
345                ASN1_item_ex_free(pval, it);
346                return -1;
347            }
348            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_NO_MATCHING_CHOICE_TYPE);
349            goto err;
350        }
351
352        asn1_set_choice_selector(pval, i, it);
353        *in = p;
354        if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
355            goto auxerr;
356        return 1;
357
358    case ASN1_ITYPE_NDEF_SEQUENCE:
359    case ASN1_ITYPE_SEQUENCE:
360        p = *in;
361        tmplen = len;
362
363        /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
364        if (tag == -1) {
365            tag = V_ASN1_SEQUENCE;
366            aclass = V_ASN1_UNIVERSAL;
367        }
368        /* Get SEQUENCE length and update len, p */
369        ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
370                              &p, len, tag, aclass, opt, ctx);
371        if (!ret) {
372            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
373            goto err;
374        } else if (ret == -1)
375            return -1;
376        if (aux && (aux->flags & ASN1_AFLG_BROKEN)) {
377            len = tmplen - (p - *in);
378            seq_nolen = 1;
379        }
380        /* If indefinite we don't do a length check */
381        else
382            seq_nolen = seq_eoc;
383        if (!cst) {
384            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
385            goto err;
386        }
387
388        if (!*pval && !ASN1_item_ex_new(pval, it)) {
389            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
390            goto err;
391        }
392
393        if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
394            goto auxerr;
395
396        /* Free up and zero any ADB found */
397        for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
398            if (tt->flags & ASN1_TFLG_ADB_MASK) {
399                const ASN1_TEMPLATE *seqtt;
400                ASN1_VALUE **pseqval;
401                seqtt = asn1_do_adb(pval, tt, 1);
402                pseqval = asn1_get_field_ptr(pval, seqtt);
403                ASN1_template_free(pseqval, seqtt);
404            }
405        }
406
407        /* Get each field entry */
408        for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
409            const ASN1_TEMPLATE *seqtt;
410            ASN1_VALUE **pseqval;
411            seqtt = asn1_do_adb(pval, tt, 1);
412            if (!seqtt)
413                goto err;
414            pseqval = asn1_get_field_ptr(pval, seqtt);
415            /* Have we ran out of data? */
416            if (!len)
417                break;
418            q = p;
419            if (asn1_check_eoc(&p, len)) {
420                if (!seq_eoc) {
421                    ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_UNEXPECTED_EOC);
422                    goto err;
423                }
424                len -= p - q;
425                seq_eoc = 0;
426                q = p;
427                break;
428            }
429            /*
430             * This determines the OPTIONAL flag value. The field cannot be
431             * omitted if it is the last of a SEQUENCE and there is still
432             * data to be read. This isn't strictly necessary but it
433             * increases efficiency in some cases.
434             */
435            if (i == (it->tcount - 1))
436                isopt = 0;
437            else
438                isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
439            /*
440             * attempt to read in field, allowing each to be OPTIONAL
441             */
442
443            ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, ctx);
444            if (!ret) {
445                errtt = seqtt;
446                goto err;
447            } else if (ret == -1) {
448                /*
449                 * OPTIONAL component absent. Free and zero the field.
450                 */
451                ASN1_template_free(pseqval, seqtt);
452                continue;
453            }
454            /* Update length */
455            len -= p - q;
456        }
457
458        /* Check for EOC if expecting one */
459        if (seq_eoc && !asn1_check_eoc(&p, len)) {
460            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
461            goto err;
462        }
463        /* Check all data read */
464        if (!seq_nolen && len) {
465            ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_SEQUENCE_LENGTH_MISMATCH);
466            goto err;
467        }
468
469        /*
470         * If we get here we've got no more data in the SEQUENCE, however we
471         * may not have read all fields so check all remaining are OPTIONAL
472         * and clear any that are.
473         */
474        for (; i < it->tcount; tt++, i++) {
475            const ASN1_TEMPLATE *seqtt;
476            seqtt = asn1_do_adb(pval, tt, 1);
477            if (!seqtt)
478                goto err;
479            if (seqtt->flags & ASN1_TFLG_OPTIONAL) {
480                ASN1_VALUE **pseqval;
481                pseqval = asn1_get_field_ptr(pval, seqtt);
482                ASN1_template_free(pseqval, seqtt);
483            } else {
484                errtt = seqtt;
485                ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_FIELD_MISSING);
486                goto err;
487            }
488        }
489        /* Save encoding */
490        if (!asn1_enc_save(pval, *in, p - *in, it))
491            goto auxerr;
492        *in = p;
493        if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
494            goto auxerr;
495        return 1;
496
497    default:
498        return 0;
499    }
500 auxerr:
501    ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_AUX_ERROR);
502 err:
503    ASN1_item_ex_free(pval, it);
504    if (errtt)
505        ERR_add_error_data(4, "Field=", errtt->field_name,
506                           ", Type=", it->sname);
507    else
508        ERR_add_error_data(2, "Type=", it->sname);
509    return 0;
510}
511
512/*
513 * Templates are handled with two separate functions. One handles any
514 * EXPLICIT tag and the other handles the rest.
515 */
516
517static int asn1_template_ex_d2i(ASN1_VALUE **val,
518                                const unsigned char **in, long inlen,
519                                const ASN1_TEMPLATE *tt, char opt,
520                                ASN1_TLC *ctx)
521{
522    int flags, aclass;
523    int ret;
524    long len;
525    const unsigned char *p, *q;
526    char exp_eoc;
527    if (!val)
528        return 0;
529    flags = tt->flags;
530    aclass = flags & ASN1_TFLG_TAG_CLASS;
531
532    p = *in;
533
534    /* Check if EXPLICIT tag expected */
535    if (flags & ASN1_TFLG_EXPTAG) {
536        char cst;
537        /*
538         * Need to work out amount of data available to the inner content and
539         * where it starts: so read in EXPLICIT header to get the info.
540         */
541        ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
542                              &p, inlen, tt->tag, aclass, opt, ctx);
543        q = p;
544        if (!ret) {
545            ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
546            return 0;
547        } else if (ret == -1)
548            return -1;
549        if (!cst) {
550            ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
551                    ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
552            return 0;
553        }
554        /* We've found the field so it can't be OPTIONAL now */
555        ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
556        if (!ret) {
557            ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
558            return 0;
559        }
560        /* We read the field in OK so update length */
561        len -= p - q;
562        if (exp_eoc) {
563            /* If NDEF we must have an EOC here */
564            if (!asn1_check_eoc(&p, len)) {
565                ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I, ASN1_R_MISSING_EOC);
566                goto err;
567            }
568        } else {
569            /*
570             * Otherwise we must hit the EXPLICIT tag end or its an error
571             */
572            if (len) {
573                ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
574                        ASN1_R_EXPLICIT_LENGTH_MISMATCH);
575                goto err;
576            }
577        }
578    } else
579        return asn1_template_noexp_d2i(val, in, inlen, tt, opt, ctx);
580
581    *in = p;
582    return 1;
583
584 err:
585    ASN1_template_free(val, tt);
586    return 0;
587}
588
589static int asn1_template_noexp_d2i(ASN1_VALUE **val,
590                                   const unsigned char **in, long len,
591                                   const ASN1_TEMPLATE *tt, char opt,
592                                   ASN1_TLC *ctx)
593{
594    int flags, aclass;
595    int ret;
596    const unsigned char *p, *q;
597    if (!val)
598        return 0;
599    flags = tt->flags;
600    aclass = flags & ASN1_TFLG_TAG_CLASS;
601
602    p = *in;
603    q = p;
604
605    if (flags & ASN1_TFLG_SK_MASK) {
606        /* SET OF, SEQUENCE OF */
607        int sktag, skaclass;
608        char sk_eoc;
609        /* First work out expected inner tag value */
610        if (flags & ASN1_TFLG_IMPTAG) {
611            sktag = tt->tag;
612            skaclass = aclass;
613        } else {
614            skaclass = V_ASN1_UNIVERSAL;
615            if (flags & ASN1_TFLG_SET_OF)
616                sktag = V_ASN1_SET;
617            else
618                sktag = V_ASN1_SEQUENCE;
619        }
620        /* Get the tag */
621        ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
622                              &p, len, sktag, skaclass, opt, ctx);
623        if (!ret) {
624            ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
625            return 0;
626        } else if (ret == -1)
627            return -1;
628        if (!*val)
629            *val = (ASN1_VALUE *)sk_new_null();
630        else {
631            /*
632             * We've got a valid STACK: free up any items present
633             */
634            STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val;
635            ASN1_VALUE *vtmp;
636            while (sk_ASN1_VALUE_num(sktmp) > 0) {
637                vtmp = sk_ASN1_VALUE_pop(sktmp);
638                ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item));
639            }
640        }
641
642        if (!*val) {
643            ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE);
644            goto err;
645        }
646
647        /* Read as many items as we can */
648        while (len > 0) {
649            ASN1_VALUE *skfield;
650            q = p;
651            /* See if EOC found */
652            if (asn1_check_eoc(&p, len)) {
653                if (!sk_eoc) {
654                    ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
655                            ASN1_R_UNEXPECTED_EOC);
656                    goto err;
657                }
658                len -= p - q;
659                sk_eoc = 0;
660                break;
661            }
662            skfield = NULL;
663            if (!ASN1_item_ex_d2i(&skfield, &p, len,
664                                  ASN1_ITEM_ptr(tt->item), -1, 0, 0, ctx)) {
665                ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
666                        ERR_R_NESTED_ASN1_ERROR);
667                goto err;
668            }
669            len -= p - q;
670            if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) {
671                ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_MALLOC_FAILURE);
672                goto err;
673            }
674        }
675        if (sk_eoc) {
676            ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ASN1_R_MISSING_EOC);
677            goto err;
678        }
679    } else if (flags & ASN1_TFLG_IMPTAG) {
680        /* IMPLICIT tagging */
681        ret = ASN1_item_ex_d2i(val, &p, len,
682                               ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt,
683                               ctx);
684        if (!ret) {
685            ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
686            goto err;
687        } else if (ret == -1)
688            return -1;
689    } else {
690        /* Nothing special */
691        ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
692                               -1, 0, opt, ctx);
693        if (!ret) {
694            ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I, ERR_R_NESTED_ASN1_ERROR);
695            goto err;
696        } else if (ret == -1)
697            return -1;
698    }
699
700    *in = p;
701    return 1;
702
703 err:
704    ASN1_template_free(val, tt);
705    return 0;
706}
707
708static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
709                                 const unsigned char **in, long inlen,
710                                 const ASN1_ITEM *it,
711                                 int tag, int aclass, char opt, ASN1_TLC *ctx)
712{
713    int ret = 0, utype;
714    long plen;
715    char cst, inf, free_cont = 0;
716    const unsigned char *p;
717    BUF_MEM buf;
718    const unsigned char *cont = NULL;
719    long len;
720    if (!pval) {
721        ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_NULL);
722        return 0;               /* Should never happen */
723    }
724
725    if (it->itype == ASN1_ITYPE_MSTRING) {
726        utype = tag;
727        tag = -1;
728    } else
729        utype = it->utype;
730
731    if (utype == V_ASN1_ANY) {
732        /* If type is ANY need to figure out type from tag */
733        unsigned char oclass;
734        if (tag >= 0) {
735            ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_ILLEGAL_TAGGED_ANY);
736            return 0;
737        }
738        if (opt) {
739            ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
740                    ASN1_R_ILLEGAL_OPTIONAL_ANY);
741            return 0;
742        }
743        p = *in;
744        ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
745                              &p, inlen, -1, 0, 0, ctx);
746        if (!ret) {
747            ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
748            return 0;
749        }
750        if (oclass != V_ASN1_UNIVERSAL)
751            utype = V_ASN1_OTHER;
752    }
753    if (tag == -1) {
754        tag = utype;
755        aclass = V_ASN1_UNIVERSAL;
756    }
757    p = *in;
758    /* Check header */
759    ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
760                          &p, inlen, tag, aclass, opt, ctx);
761    if (!ret) {
762        ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
763        return 0;
764    } else if (ret == -1)
765        return -1;
766    ret = 0;
767    /* SEQUENCE, SET and "OTHER" are left in encoded form */
768    if ((utype == V_ASN1_SEQUENCE)
769        || (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER)) {
770        /*
771         * Clear context cache for type OTHER because the auto clear when we
772         * have a exact match wont work
773         */
774        if (utype == V_ASN1_OTHER) {
775            asn1_tlc_clear(ctx);
776        }
777        /* SEQUENCE and SET must be constructed */
778        else if (!cst) {
779            ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
780                    ASN1_R_TYPE_NOT_CONSTRUCTED);
781            return 0;
782        }
783
784        cont = *in;
785        /* If indefinite length constructed find the real end */
786        if (inf) {
787            if (!asn1_find_end(&p, plen, inf))
788                goto err;
789            len = p - cont;
790        } else {
791            len = p - cont + plen;
792            p += plen;
793            buf.data = NULL;
794        }
795    } else if (cst) {
796        if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN
797            || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER
798            || utype == V_ASN1_ENUMERATED) {
799            ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ASN1_R_TYPE_NOT_PRIMITIVE);
800            return 0;
801        }
802        buf.length = 0;
803        buf.max = 0;
804        buf.data = NULL;
805        /*
806         * Should really check the internal tags are correct but some things
807         * may get this wrong. The relevant specs say that constructed string
808         * types should be OCTET STRINGs internally irrespective of the type.
809         * So instead just check for UNIVERSAL class and ignore the tag.
810         */
811        if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0)) {
812            free_cont = 1;
813            goto err;
814        }
815        len = buf.length;
816        /* Append a final null to string */
817        if (!BUF_MEM_grow_clean(&buf, len + 1)) {
818            ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_MALLOC_FAILURE);
819            return 0;
820        }
821        buf.data[len] = 0;
822        cont = (const unsigned char *)buf.data;
823        free_cont = 1;
824    } else {
825        cont = p;
826        len = plen;
827        p += plen;
828    }
829
830    /* We now have content length and type: translate into a structure */
831    if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
832        goto err;
833
834    *in = p;
835    ret = 1;
836 err:
837    if (free_cont && buf.data)
838        OPENSSL_free(buf.data);
839    return ret;
840}
841
842/* Translate ASN1 content octets into a structure */
843
844int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
845                int utype, char *free_cont, const ASN1_ITEM *it)
846{
847    ASN1_VALUE **opval = NULL;
848    ASN1_STRING *stmp;
849    ASN1_TYPE *typ = NULL;
850    int ret = 0;
851    const ASN1_PRIMITIVE_FUNCS *pf;
852    ASN1_INTEGER **tint;
853    pf = it->funcs;
854
855    if (pf && pf->prim_c2i)
856        return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
857    /* If ANY type clear type and set pointer to internal value */
858    if (it->utype == V_ASN1_ANY) {
859        if (!*pval) {
860            typ = ASN1_TYPE_new();
861            if (typ == NULL)
862                goto err;
863            *pval = (ASN1_VALUE *)typ;
864        } else
865            typ = (ASN1_TYPE *)*pval;
866
867        if (utype != typ->type)
868            ASN1_TYPE_set(typ, utype, NULL);
869        opval = pval;
870        pval = &typ->value.asn1_value;
871    }
872    switch (utype) {
873    case V_ASN1_OBJECT:
874        if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
875            goto err;
876        break;
877
878    case V_ASN1_NULL:
879        if (len) {
880            ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_NULL_IS_WRONG_LENGTH);
881            goto err;
882        }
883        *pval = (ASN1_VALUE *)1;
884        break;
885
886    case V_ASN1_BOOLEAN:
887        if (len != 1) {
888            ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
889            goto err;
890        } else {
891            ASN1_BOOLEAN *tbool;
892            tbool = (ASN1_BOOLEAN *)pval;
893            *tbool = *cont;
894        }
895        break;
896
897    case V_ASN1_BIT_STRING:
898        if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
899            goto err;
900        break;
901
902    case V_ASN1_INTEGER:
903    case V_ASN1_NEG_INTEGER:
904    case V_ASN1_ENUMERATED:
905    case V_ASN1_NEG_ENUMERATED:
906        tint = (ASN1_INTEGER **)pval;
907        if (!c2i_ASN1_INTEGER(tint, &cont, len))
908            goto err;
909        /* Fixup type to match the expected form */
910        (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
911        break;
912
913    case V_ASN1_OCTET_STRING:
914    case V_ASN1_NUMERICSTRING:
915    case V_ASN1_PRINTABLESTRING:
916    case V_ASN1_T61STRING:
917    case V_ASN1_VIDEOTEXSTRING:
918    case V_ASN1_IA5STRING:
919    case V_ASN1_UTCTIME:
920    case V_ASN1_GENERALIZEDTIME:
921    case V_ASN1_GRAPHICSTRING:
922    case V_ASN1_VISIBLESTRING:
923    case V_ASN1_GENERALSTRING:
924    case V_ASN1_UNIVERSALSTRING:
925    case V_ASN1_BMPSTRING:
926    case V_ASN1_UTF8STRING:
927    case V_ASN1_OTHER:
928    case V_ASN1_SET:
929    case V_ASN1_SEQUENCE:
930    default:
931        if (utype == V_ASN1_BMPSTRING && (len & 1)) {
932            ASN1err(ASN1_F_ASN1_EX_C2I, ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
933            goto err;
934        }
935        if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) {
936            ASN1err(ASN1_F_ASN1_EX_C2I,
937                    ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
938            goto err;
939        }
940        /* All based on ASN1_STRING and handled the same */
941        if (!*pval) {
942            stmp = ASN1_STRING_type_new(utype);
943            if (!stmp) {
944                ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE);
945                goto err;
946            }
947            *pval = (ASN1_VALUE *)stmp;
948        } else {
949            stmp = (ASN1_STRING *)*pval;
950            stmp->type = utype;
951        }
952        /* If we've already allocated a buffer use it */
953        if (*free_cont) {
954            if (stmp->data)
955                OPENSSL_free(stmp->data);
956            stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
957            stmp->length = len;
958            *free_cont = 0;
959        } else {
960            if (!ASN1_STRING_set(stmp, cont, len)) {
961                ASN1err(ASN1_F_ASN1_EX_C2I, ERR_R_MALLOC_FAILURE);
962                ASN1_STRING_free(stmp);
963                *pval = NULL;
964                goto err;
965            }
966        }
967        break;
968    }
969    /* If ASN1_ANY and NULL type fix up value */
970    if (typ && (utype == V_ASN1_NULL))
971        typ->value.ptr = NULL;
972
973    ret = 1;
974 err:
975    if (!ret) {
976        ASN1_TYPE_free(typ);
977        if (opval)
978            *opval = NULL;
979    }
980    return ret;
981}
982
983/*
984 * This function finds the end of an ASN1 structure when passed its maximum
985 * length, whether it is indefinite length and a pointer to the content. This
986 * is more efficient than calling asn1_collect because it does not recurse on
987 * each indefinite length header.
988 */
989
990static int asn1_find_end(const unsigned char **in, long len, char inf)
991{
992    int expected_eoc;
993    long plen;
994    const unsigned char *p = *in, *q;
995    /* If not indefinite length constructed just add length */
996    if (inf == 0) {
997        *in += len;
998        return 1;
999    }
1000    expected_eoc = 1;
1001    /*
1002     * Indefinite length constructed form. Find the end when enough EOCs are
1003     * found. If more indefinite length constructed headers are encountered
1004     * increment the expected eoc count otherwise just skip to the end of the
1005     * data.
1006     */
1007    while (len > 0) {
1008        if (asn1_check_eoc(&p, len)) {
1009            expected_eoc--;
1010            if (expected_eoc == 0)
1011                break;
1012            len -= 2;
1013            continue;
1014        }
1015        q = p;
1016        /* Just read in a header: only care about the length */
1017        if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
1018                             -1, 0, 0, NULL)) {
1019            ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
1020            return 0;
1021        }
1022        if (inf)
1023            expected_eoc++;
1024        else
1025            p += plen;
1026        len -= p - q;
1027    }
1028    if (expected_eoc) {
1029        ASN1err(ASN1_F_ASN1_FIND_END, ASN1_R_MISSING_EOC);
1030        return 0;
1031    }
1032    *in = p;
1033    return 1;
1034}
1035
1036/*
1037 * This function collects the asn1 data from a constructred string type into
1038 * a buffer. The values of 'in' and 'len' should refer to the contents of the
1039 * constructed type and 'inf' should be set if it is indefinite length.
1040 */
1041
1042#ifndef ASN1_MAX_STRING_NEST
1043/*
1044 * This determines how many levels of recursion are permitted in ASN1 string
1045 * types. If it is not limited stack overflows can occur. If set to zero no
1046 * recursion is allowed at all. Although zero should be adequate examples
1047 * exist that require a value of 1. So 5 should be more than enough.
1048 */
1049# define ASN1_MAX_STRING_NEST 5
1050#endif
1051
1052static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
1053                        char inf, int tag, int aclass, int depth)
1054{
1055    const unsigned char *p, *q;
1056    long plen;
1057    char cst, ininf;
1058    p = *in;
1059    inf &= 1;
1060    /*
1061     * If no buffer and not indefinite length constructed just pass over the
1062     * encoded data
1063     */
1064    if (!buf && !inf) {
1065        *in += len;
1066        return 1;
1067    }
1068    while (len > 0) {
1069        q = p;
1070        /* Check for EOC */
1071        if (asn1_check_eoc(&p, len)) {
1072            /*
1073             * EOC is illegal outside indefinite length constructed form
1074             */
1075            if (!inf) {
1076                ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_UNEXPECTED_EOC);
1077                return 0;
1078            }
1079            inf = 0;
1080            break;
1081        }
1082
1083        if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
1084                             len, tag, aclass, 0, NULL)) {
1085            ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
1086            return 0;
1087        }
1088
1089        /* If indefinite length constructed update max length */
1090        if (cst) {
1091            if (depth >= ASN1_MAX_STRING_NEST) {
1092                ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING);
1093                return 0;
1094            }
1095            if (!asn1_collect(buf, &p, plen, ininf, tag, aclass, depth + 1))
1096                return 0;
1097        } else if (plen && !collect_data(buf, &p, plen))
1098            return 0;
1099        len -= p - q;
1100    }
1101    if (inf) {
1102        ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_MISSING_EOC);
1103        return 0;
1104    }
1105    *in = p;
1106    return 1;
1107}
1108
1109static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1110{
1111    int len;
1112    if (buf) {
1113        len = buf->length;
1114        if (!BUF_MEM_grow_clean(buf, len + plen)) {
1115            ASN1err(ASN1_F_COLLECT_DATA, ERR_R_MALLOC_FAILURE);
1116            return 0;
1117        }
1118        memcpy(buf->data + len, *p, plen);
1119    }
1120    *p += plen;
1121    return 1;
1122}
1123
1124/* Check for ASN1 EOC and swallow it if found */
1125
1126static int asn1_check_eoc(const unsigned char **in, long len)
1127{
1128    const unsigned char *p;
1129    if (len < 2)
1130        return 0;
1131    p = *in;
1132    if (!p[0] && !p[1]) {
1133        *in += 2;
1134        return 1;
1135    }
1136    return 0;
1137}
1138
1139/*
1140 * Check an ASN1 tag and length: a bit like ASN1_get_object but it sets the
1141 * length for indefinite length constructed form, we don't know the exact
1142 * length but we can set an upper bound to the amount of data available minus
1143 * the header length just read.
1144 */
1145
1146static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1147                           char *inf, char *cst,
1148                           const unsigned char **in, long len,
1149                           int exptag, int expclass, char opt, ASN1_TLC *ctx)
1150{
1151    int i;
1152    int ptag, pclass;
1153    long plen;
1154    const unsigned char *p, *q;
1155    p = *in;
1156    q = p;
1157
1158    if (ctx && ctx->valid) {
1159        i = ctx->ret;
1160        plen = ctx->plen;
1161        pclass = ctx->pclass;
1162        ptag = ctx->ptag;
1163        p += ctx->hdrlen;
1164    } else {
1165        i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
1166        if (ctx) {
1167            ctx->ret = i;
1168            ctx->plen = plen;
1169            ctx->pclass = pclass;
1170            ctx->ptag = ptag;
1171            ctx->hdrlen = p - q;
1172            ctx->valid = 1;
1173            /*
1174             * If definite length, and no error, length + header can't exceed
1175             * total amount of data available.
1176             */
1177            if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) {
1178                ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_TOO_LONG);
1179                asn1_tlc_clear(ctx);
1180                return 0;
1181            }
1182        }
1183    }
1184
1185    if (i & 0x80) {
1186        ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_BAD_OBJECT_HEADER);
1187        asn1_tlc_clear(ctx);
1188        return 0;
1189    }
1190    if (exptag >= 0) {
1191        if ((exptag != ptag) || (expclass != pclass)) {
1192            /*
1193             * If type is OPTIONAL, not an error: indicate missing type.
1194             */
1195            if (opt)
1196                return -1;
1197            asn1_tlc_clear(ctx);
1198            ASN1err(ASN1_F_ASN1_CHECK_TLEN, ASN1_R_WRONG_TAG);
1199            return 0;
1200        }
1201        /*
1202         * We have a tag and class match: assume we are going to do something
1203         * with it
1204         */
1205        asn1_tlc_clear(ctx);
1206    }
1207
1208    if (i & 1)
1209        plen = len - (p - q);
1210
1211    if (inf)
1212        *inf = i & 1;
1213
1214    if (cst)
1215        *cst = i & V_ASN1_CONSTRUCTED;
1216
1217    if (olen)
1218        *olen = plen;
1219
1220    if (oclass)
1221        *oclass = pclass;
1222
1223    if (otag)
1224        *otag = ptag;
1225
1226    *in = p;
1227    return 1;
1228}
1229